Radio communication device with integrated antenna, transmitter, and receiver

ABSTRACT

A dielectric multilayer substrate  220  is formed by laminating first through third dielectric layers  201  through  203 . A plurality of conductor patches  204   a  through  204   d  are arranged on the upper surface of the first dielectric layer  201 , and a microstrip line  205  for antenna feeding is arranged between the first and second dielectric layers. A ground layer  206  is arranged between the second and third dielectric layers  202  and  203 , and microstrip lines  208   a  and  208   b  for a high-frequency circuit are arranged on the lower surface of the third dielectric layer  203 . The microstrip line  205  for antenna feeding and the microstrip line  208   a  for the high-frequency circuit are electromagnetically coupled with each other via a slot hole  207  provided for the ground layer  206 . With this arrangement, the efficiency and directivity of the antenna are improved.

TECHNICAL FIELD

[0001] The present invention relates to an antenna-integrated radiocommunication device, transmitter and receiver provided with an antennafunction to be used for microwave communications.

BACKGROUND ART

[0002] Recently, in accordance with improvements in the processing speedof information processing apparatuses, developments in resolution ofimage processing apparatuses and so on, attention has been paid tohigh-speed large-capacity personal communications at high frequencies ofmicrowaves and the like. Particularly, in the milliwave band, power lossin the connection portions of an antenna and a high-frequency circuitbecomes increased, and therefore, it is attempted to develop anantenna-integrated radio communication device in which an antenna isintegrated with a high-frequency circuit.

[0003] As an antenna-integrated radio communication device, there is theone disclosed in Japanese Patent Laid-Open Publication No. HEI 9-237867.As shown in FIG. 8, this antenna-integrated radio communication deviceincludes an antenna circuit substrate A in which an antenna element 3and a high-frequency line 4 for feeding the antenna element 3 are formedon a first dielectric substrate 2 and a high-frequency device circuitsubstrate B in which a high-frequency device 9 is housed in a cavity 8formed in a part of a second dielectric substrate 7 and sealed with alid member 10 and a transmission line 11 for transmitting a signal tothe high-frequency device 9 is formed. The antenna circuit substrate Aand the device circuit substrate B are laminated and integrated witheach other, and the high-frequency line 4 of the antenna circuitsubstrate A and the transmission line 11 of the high-frequency devicecircuit substrate B are electromagnetically coupled and connected witheach other via a slot 6.

[0004] Moreover, as another antenna-integrated radio communicationdevice, there is the one described in Japanese Patent Laid-OpenPublication No. HEI 8-250913. As shown in FIG. 9, thisantenna-integrated radio communication device includes a base 41constructed of upper and lower dielectric layers 41 a and 41 b and aground layer 41 c placed between the dielectric layers 41 a and 41 b,and the ground layer 41 c is provided with a slot portion 41 d.Moreover, a flat antenna 41 e is formed on the lower surface of apackage 3 that seals and houses a semiconductor integrated circuit, anda microstrip line 91 for feeding is formed on the package inner surfaceside of the upper dielectric layer 41 a. Then, this microstrip line 91is electrically connected to an output terminal 2 a and an inputterminal 93 of an MMIC (Monolithic Microwave Integrated Circuit) 92 withbonding wires 2 b and 94.

[0005] In the antenna-integrated radio communication device shown inFIG. 8, ground layers 5 and 12 exist above and below the high-frequencyline 4 that feeds the antenna element 3. Therefore, the upper and lowerground layers 5 and 12 do not become equipotential particularly at veryhigh frequencies as in the milliwave band, and electric power isconverted into unnecessary electromagnetic waves in a parallel platemode to propagate between the upper and lower ground layers 5 and 12,loosing the electric power from substrate end surfaces. As a method forrestraining this unnecessary mode, there can be considered a method forequalizing the potentials of the two ground layers by connecting theupper and lower ground layers via a lot of through holes. However,inductance of the through holes becomes unignorable as the frequencybecomes higher, and therefore, this method has a limitation. As a resultof the generation of electromagnetic waves in the unnecessary modedescribed above, there is a problem that the efficiency of the antennaelement 3 is reduced. Moreover, if substrate materials of differentmaterial properties are laminated in the antenna-integrated radiocommunication device, there is a problem that the semiconductor chipmounting reliability is degraded due to the manufacturing problems suchas lamination displacement and exfoliation and the warp of thesubstrates because of differences in the thermal expansion coefficientbetween them.

[0006] Moreover, in the antenna-integrated radio communication deviceshown in FIG. 9, in order to form an array of flat antennas 41 e, it isrequired to branch the feeding microstrip line 91 to feed each flatantenna 41 e and house the feeding microstrip line 91 in the samepackage as that of the MMIC 92. However, unnecessary electromagneticwaves radiated from the feeding microstrip line 91 and the MMIC 92 exertadverse influences on them, possibly causing not only a reduction inefficiency but also malfunction.

[0007] As described above, it has been difficult for the conventionalantenna-integrated radio communication devices shown in FIG. 8 and FIG.9 to concurrently satisfy the antenna efficiency, the directivity of theformed array and the semiconductor chip mounting reliability.

DISCLOSURE OF THE INVENTION

[0008] Accordingly, the object of the present invention is to provide anantenna-integrated radio communication device capable of improving theefficiency and directivity of the antenna, improving the semiconductorchip mounting reliability with restrained warp of the substrate andpreventing the malfunctioning of the high-frequency circuit as well as atransmitter and a receiver employing the communication device.

[0009] In order to achieve the aforementioned object, the presentinvention provides an antenna-integrated radio communication devicehaving a dielectric multilayer substrate in which a plurality ofdielectric layers are laminated and a high-frequency circuit on whichsemiconductor chips are mounted, wherein

[0010] a plurality of conductor patches, an antenna feeder line forfeeding the plurality of conductor patches, one ground layer and thehigh-frequency circuit connected to the antenna feeder line areseparately arranged on an upper surface, between layers and on a lowersurface, respectively, of the dielectric multilayer substrate, and theone ground layer is arranged between an antenna section comprised of theplurality of conductor patches and the antenna feeder line and thehigh-frequency circuit.

[0011] According to the antenna-integrated radio communication device ofthe above-mentioned construction, the plurality of conductor patches,the antenna feeder line, the ground layer and the high-frequency circuitare separately arranged on the upper surface, between the layers and onthe lower surface, respectively, of the dielectric multilayer substrate,and the ground layer is arranged between the antenna section constructedof the plurality of conductor patches and the antenna feeder line, andthe high-frequency circuit. With this arrangement, the antenna sectionand the high-frequency circuit are spatially separated from each otherby the ground layer, and therefore, the mutual adverse influences of theantenna circuit and the high-frequency circuit can be eliminated.Moreover, the ground layer is only one layer, and therefore, the antennafeeder line becomes able to perform the transmission in the desiredquasi-TEM mode even at a high frequency in the milliwave band.Therefore, the efficiency and directivity of the antenna can beimproved, and the high-frequency circuit can be prevented frommalfunctioning. Furthermore, the plurality of conductor patches and theantenna feeder line are formed in different layers, and therefore, theefficiency of the antenna and the characteristics of the antenna feederline can be independently optimized.

[0012] Moreover, in one embodiment, the dielectric multilayer substrateis a dielectric multilayer substrate comprised of a first dielectriclayer, a second dielectric layer and a third dielectric layer,

[0013] the plurality of conductor patches are arranged on an uppersurface of the first dielectric layer of the dielectric multilayersubstrate,

[0014] the antenna feeder line is arranged between the first dielectriclayer and the second dielectric layer,

[0015] the ground layer is arranged between the second dielectric layerand the third dielectric layer,

[0016] the high-frequency circuit is arranged on a lower surface of thethird dielectric layer of the dielectric multilayer substrate, and

[0017] the antenna feeder line is electromagnetically coupled with thehigh-frequency circuit via a slot hole provided for the ground layer.

[0018] According to the antenna-integrated radio communication device ofthe above-mentioned embodiment, the dielectric multilayer substrate hasthe plurality of conductor patches provided on its upper surface, theantenna feeder line provided between the first and second dielectriclayers, the ground layer provided between the second and thirddielectric layers and the high-frequency circuit provided on the lowersurface, and the antenna feeder line is electromagnetically coupled withthe high-frequency circuit via the slot hole provided for the groundlayer. This allows the obtainment of an optimum structure capable ofeasily improving the efficiency and directivity of the antenna andpreventing the high-frequency circuit from malfunctioning.

[0019] Moreover, in one embodiment, the plurality of conductor patchesare arranged in an array form,

[0020] the antenna feeder line is branched into a plurality of lines,and the plurality of conductor patches and end portions of the branchesof the antenna feeder line overlap each other.

[0021] According to the above-mentioned embodiment, the directivity ofthe antenna can be efficiently improved with the plurality of conductorpatches arranged in an array form and the end portions of the branchesof the antenna feeder line overlapping the patches.

[0022] Moreover, in one embodiment, a distance in a lengthwise directionof the antenna feeder line in a region where the plurality of conductorpatches and the end portions of the branches of the antenna feeder lineoverlap each other is approximately a quarter of an effective wavelengthof a prescribed electromagnetic wave.

[0023] According to the antenna-integrated radio communication device ofthe above-mentioned embodiment, the distance in the lengthwise directionof the antenna feeder line in the region where the plurality ofconductor patches and the end portions of the branches of the antennafeeder line overlap each other is approximately a quarter of theeffective wavelength of the prescribed electromagnetic wave. With thisstructure, loss due to reflections on the end portions of the antennafeeder line can be reduced, enabling the efficient feeding of eachconductor patch from the antenna feeder line.

[0024] Moreover, in one embodiment, the dielectric layers of thedielectric multilayer substrate are formed by integrally baking aceramic material that has a relative dielectric constant of 4 to 10.

[0025] According to the above-mentioned embodiment, by forming thedielectric layer of the dielectric multilayer substrate by the integralbaking of the ceramic material that has a relative dielectric constantof 4 to 10, the structure of the dielectric multilayer substrate can beaccurately provided. Moreover, strong substrate strength can be obtainedby the use of the ceramic material, and the warp of the substrate isrestrained, allowing the semiconductor chip mounting reliability to beimproved.

[0026] Moreover, this invention provides an antenna-integrated radiocommunication device, wherein a plurality of conductor patches, anantenna feeder line, a ground layer and a high-frequency circuit areprovided in order from an upper surface to a lower surface of thedielectric multilayer substrate on the upper surface, between layers andon the lower surface, respectively, of the dielectric multilayersubstrate in which three dielectric layers are laminated.

[0027] According to the antenna-integrated radio communication device ofthe above-mentioned construction, the antenna section constructed of theplurality of conductor patches and the antenna feeder line, and thehigh-frequency circuit are spatially separated from each other by theground layer, and therefore, the mutual adverse influences of theantenna section and the high-frequency circuit can be eliminated.Moreover, the ground layer is only one layer, and therefore, the antennafeeder line can perform transmission in the desired quasi-TEM mode evenat a high frequency in the milliwave band. Therefore, the efficiency anddirectivity of the antenna can be improved, and the high-frequencycircuit can be prevented from malfunctioning. Furthermore, the pluralityof conductor patches and the antenna feeder line are formed on differentlayers, and therefore, the efficiency of the antenna and thecharacteristics of the antenna feeder line can be independentlyoptimized.

[0028] Moreover, in one embodiment, each dielectric layer of thedielectric multilayer substrate has a thickness of 100 microns to 200microns.

[0029] According to the above-mentioned embodiment, by making eachdielectric layer of the dielectric multilayer substrate have a thicknessof not greater than 200 microns, it is enabled to perform transmissionin the desired quasi-TEM mode between the microstrip line used for theantenna feeder line and the ground layer at a frequency of, for example,60 GHz when the dielectric layer has a relative dielectric constant of 4to 10. If the thickness of each dielectric layer exceeds 200 microns,then the transmission loss of the microstrip line used for the antennafeeder line is increased. When the thickness of each dielectric layer isnot greater than 100 microns, the interval between the conductor patchand the ground layer becomes narrow, and this reduces the antennaradiation efficiency and reduces the strength of the dielectricmultilayer substrate.

[0030] Moreover, this invention provides a transmitter and a receiveremploying the above antenna-integrated radio communication device.

[0031] According to the transmitter and the receiver of theabove-mentioned construction, the transmitter and the receiver can bedownsized. Moreover, by virtue of the formation of the antenna sectionand the high-frequency circuit on the upper and lower surfaces,respectively, of the dielectric substrate, signal loss between theantenna section and the high-frequency circuit can be reduced, and thecommunication distance can be increased without increasing theconsumption power.

BRIEF DESCRIPTION OF THE DRAWINGS

[0032]FIG. 1 is a sectional view of an antenna-integrated radiocommunication device according to a first embodiment of this invention;

[0033]FIG. 2 is a view showing the positional relation between conductorpatches and an antenna feeding microstrip line of the aboveantenna-integrated radio communication device;

[0034]FIG. 3 is a sectional view of an antenna-integrated radiocommunication device according to a second embodiment of this invention;

[0035]FIG. 4 is a top view of the antenna section of the aboveantenna-integrated radio communication device;

[0036]FIG. 5 is a graph showing the frequency dependence of thereflection loss of the antenna of the antenna-integrated radiocommunication device of the second embodiment of this invention;

[0037]FIG. 6 is a sectional view of an antenna-integrated radiocommunication device according to a third embodiment of this invention;

[0038]FIG. 7 is a sectional view of an antenna-integrated radiocommunication device according to a fourth embodiment of this invention;

[0039]FIG. 8 is a sectional view of a prior art antenna-integrated radiocommunication device;

[0040]FIG. 9 is a sectional view of another prior art antenna-integratedradio communication device;

[0041]FIG. 10 is a sectional view of an antenna-integrated radiocommunication device according to a fifth embodiment of this invention;

[0042]FIG. 11 is a view showing the positional relation of conductorpatches, an antenna feeding microstrip line and a slot hole of the aboveantenna-integrated radio communication device;

[0043]FIG. 12 is a graph showing the frequency characteristic of theantenna gain of the antenna section of the above antenna-integratedradio communication device;

[0044]FIG. 13 is a graph showing the frequency characteristic of theinput reflection loss of the above antenna section;

[0045]FIG. 14 is a view showing the radiation pattern at 60 GHz of theabove antenna section; and

[0046]FIG. 15 is a block diagram showing the constructions of atransmitter and a receiver, each of which employs an antenna-integratedradio communication device according to a sixth embodiment of thisinvention.

BEST MODE FOR CARRYING OUT THE INVENTION

[0047] The antenna-integrated radio communication device, transmitterand receiver of this invention will be described in detail below on thebasis of the embodiments shown in the drawings.

First Embodiment

[0048]FIG. 1 is a sectional view showing the structure of theantenna-integrated radio communication device of the first embodiment ofthis invention. As shown in FIG. 1, this antenna-integrated radiocommunication device includes a dielectric multilayer substrate 220 thathas a first dielectric layer 201, a second dielectric layer 202 and athird dielectric layer 203, which are laminated together. A plurality ofconductor patches 204 a through 204 d (only the four are shown inFIG. 1) are formed in an array form on the upper surface of the firstdielectric layer 201, forming a microstrip line 205 for antenna feedingbetween the first dielectric layer 201 and the second conductor layer202. Moreover, a ground layer 206 is formed between the seconddielectric layer 202 and the third conductor layer 203, and a slot hole207 is formed in the ground layer 206. Moreover, microstrip lines 208 aand 208 b for a high-frequency circuit are formed on the surface of thethird dielectric layer 203, and MMIC's 209 a and 209 b, which aresemiconductor chips, are mounted on the microstrip lines 208 a and 208 bfor the high-frequency circuit. Then, the microstrip lines 208 a and 208b for the high-frequency circuit and the MMIC's 209 a and 209 b arecovered with a conductor lid 210.

[0049] Moreover, the ground layer 206 is connected to the conductor lid210 via through holes 211 b and 211 c and a connection portion 230.Moreover, one end of a low-frequency signal line 213 is connected to theMMIC 209 b, and a port 214 formed on the upper surface of the firstdielectric layer 201 is connected to the other end of the low-frequencysignal line 213 via a through hole 211 a. A clearance hole 212 throughwhich the through hole 211 a penetrates is provided for the ground layer206.

[0050] The microstrip line 205 for antenna feeding iselectromagnetically coupled with the microstrip line 208 a for thehigh-frequency circuit via the slot hole 207 opened on the ground layer206. Moreover, the microstrip line 205 for antenna feeding iselectromagnetically coupled with the conductor patches 204 a through 204d via the first dielectric layer 201.

[0051] By arranging the plurality of conductor patches 204 a through 204d in an array form, an antenna function of an improved directivity caneasily be obtained.

[0052] For example, FIG. 2 is a schematic view showing the positionalrelation of the conductor patches 204 and the microstrip line 205 forantenna feeding when 16-element conductor patches 204 are arranged in anarray form in the aforementioned antenna-integrated radio communicationdevice. A method for branching the microstrip line 205 for antennafeeding is similar to the conventional method, and no description isprovided therefor herein.

[0053] The functions of a transmitter that employs theantenna-integrated radio communication device of the aforementionedconstruction will be described next.

[0054] In FIG. 1, a low-frequency signal inputted to the port 214 issubjected to the processes of frequency conversion, amplification and soon by the MMIC's 209 a and 209 b. Then, a high-frequency signaloutputted from the MMIC 209 a passes through the microstrip line 208 afor the high-frequency circuit and is transmitted to the microstrip line205 for antenna feeding via the slot hole 207 and transmitted to theleading end portion of the microstrip line 205 for antenna feeding. Theleading end portion of the microstrip line 205 for antenna feeding iselectromagnetically coupled with the conductor patches 204 via the firstdielectric layer 201, and therefore, the high-frequency signal istransmitted to each of the conductor patches 204. Then, thehigh-frequency signal resonates on the surface of the conductor patches204 a through 204 d, and a large current flows to radiateelectromagnetic waves into the space.

[0055] The functions of the transmitter that emits radiation from theconductor patches 204 a through 204 d have been described above.However, the antenna section has same directivity and efficiency by areversible action also when an input wave is received from the space, itis also possible to constitute a receiver by changing the MMICconstruction. It is to be noted that the microstrip lines 208 a and 208b for the high-frequency circuit include passive circuits such as amatching circuit and a filter (not shown).

[0056] Generally, in the microstrip line, part of the electromagneticwaves that propagate in the quasi-TEM mode is converted into anunnecessary TM mode as the frequency becomes higher, and this isradiated from the edges of the dielectric multilayer substrate toincrease the loss. Accordingly, it is required to provide a reducedinterval between the transmission line and ground in order to performtransmission in the quasi-TEM mode. In the case of a high-frequencysignal at a frequency of, for example, 60 GHz, if the interval betweenthe microstrip line and the ground layer is not greater than 200 micronswith the dielectric layer having a relative dielectric constant of 4 to10, then the transmission can be regarded as the transmission in thedesired quasi-TEM mode. In the case of a patch antenna in which aplurality of conductor patches are arranged in an array form, theradiation efficiency significantly deteriorates when the intervalbetween each conductor patch and the ground layer is narrow. The higherthe dielectric constant of the dielectric substance is, the further thisbecomes significant. When a dielectric layer having a relativedielectric constant of about 4 to 10 is employed, the interval betweeneach conductor patch and the ground layer is required to be about 0.05times to 0.1 times the wavelength in the air in order to obtain asufficient radiation efficiency.

[0057] Moreover, if a radio communication device for the 60-GHz band isconsidered, the thickness of each of the dielectric layers 201, 202 and203 is set at 150 microns to 200 microns in this first embodiment. Inthis case, the interval between the microstrip line 205 for antennafeeding and the ground layer 206 is 150 microns to 200 microns, andtherefore, the microstrip line 205 for antenna feeding can be regardedas transmission in the quasi-TEM mode at 60 GHz. Moreover, an intervalbetween each conductor patch 204 and the ground layer 206 becomes 300 to400 microns, the interval being 0.06 times to 0.08 times the wavelengthin the air, meaning that sufficient radiation efficiency can beobtained. Moreover, an interval between the microstrip line 205 forantenna feeding and the microstrip lines 208 a and 208 b for thehigh-frequency circuit becomes 300 to 400 microns, meaning that asufficient degree of coupling can be obtained via the slot hole 207.Furthermore, the dielectric multilayer substrate 220 has a sufficienttotal thickness of 450 to 600 microns, and therefore, a high-strengthdielectric multilayer substrate can be obtained. The warp of thedielectric multilayer substrate is also small, and the substratemounting reliability of the MMIC chips 209 a and 209 b is improved.

[0058] As described above, by separately forming the conductor patches,the antenna feeder line, the ground layer and the high-frequency circuiton the upper surface, the lower surface and between the layers,respectively, of the dielectric multilayer substrate 220, the efficiencyof the antenna and the characteristics of the antenna feeder line can beindependently optimized. Since the antenna is spatially separated fromthe high-frequency circuit by the ground layer, the mutual adverseinfluences of the antenna and the high-frequency circuit can beeliminated.

[0059] Therefore, the efficiency and directivity of the antenna can beimproved, and the semiconductor chip mounting reliability can beimproved with the substrate warp restrained.

Second Embodiment

[0060]FIG. 3 is a sectional view showing the structure of theantenna-integrated radio communication device of the second embodimentof this invention, and FIG. 4 is a top view of the essential part of anantenna section.

[0061] As shown in FIG. 3, this antenna-integrated radio communicationdevice includes a dielectric multilayer substrate 320 that has a firstdielectric layer 301, a second dielectric layer 302 and a thirddielectric layer 303, which are laminated together. A plurality ofconductor patches 304 a through 304 d (only the four are shown in FIG.3) are formed in an array form on the upper surface of the firstdielectric layer 301, and a microstrip line 305 for antenna feeding isformed between the first dielectric layer 301 and the second dielectriclayer 302. Moreover, a ground layer 306 is formed between the seconddielectric layer 302 and the third dielectric layer 303, and a slot hole307 is formed in the ground layer 306. Moreover, microstrip lines 308 aand 308 b for a high-frequency circuit are formed on the surface of thethird dielectric layer 303, and MMIC's 309 a and 309 b, which aresemiconductor chips, are mounted on the microstrip lines 308 a and 308 bfor the high-frequency circuit. Then, the microstrip lines 308 a and 308b for the high-frequency circuit and the MMIC's 309 a and 309 b arecovered with a conductor lid 310.

[0062] Moreover, the ground layer 306 is connected to the conductor lid310 via through holes 311 b and 311 c and a connection portion 330.Moreover, one end of a low-frequency signal line 313 is connected to theMMIC 309 b, and a port 314 formed on the upper surface of the firstdielectric layer 301 is connected to the other end of the low-frequencysignal line 313 via a through hole 311 a. A clearance hole 312 throughwhich the through hole 311 a penetrates is provided for the ground layer306.

[0063] The microstrip line 305 for antenna feeding iselectromagnetically coupled with the microstrip line 308 a for thehigh-frequency circuit via the slot hole 307. Moreover, the microstripline 305 for antenna feeding is electromagnetically coupled with theconductor patches 304 via the first dielectric layer 301.

[0064] The antenna-integrated radio communication device of the secondembodiment has the same effect as that of the first embodiment.

[0065] Further, as shown in FIG. 4, one side “a” of the conductor patch304 is set to about a half of the effective wavelength, and a length “b”in the lengthwise direction of the microstrip line 305 in the regionwhere the microstrip line 305 for antenna feeding and the conductorpatch 304 overlap each other is set to about a quarter of the effectivewavelength.

[0066]FIG. 5 shows the reflection loss of the antenna section of theaforementioned antenna-integrated radio communication device. In FIG. 5,the horizontal axis represents the frequency, and the vertical axisrepresents the reflection loss. In this case, the dielectric layers areeach an alumina substrate that has a thickness of 150 microns and arelative dielectric constant of 9. As shown in FIG. 5, the reflectionloss is 10 dB or less at a frequency of 59 to 63 GHz. This means thatthe coupling of the microstrip line 305 for antenna feeding and theconductor patches 304 a through 304 d as well as the coupling of theconductor patches 304 a through 304 d and the space are satisfactoryover a wide frequency band.

Third Embodiment

[0067]FIG. 6 is a sectional view showing the structure of theantenna-integrated radio communication device of the third embodiment ofthis invention. As shown in FIG. 6, this antenna-integrated radiocommunication device includes a dielectric multilayer substrate 420 thathas a first dielectric layer 401, a second dielectric layer 402 and athird dielectric layer 403, which are laminated together. A plurality ofconductor patches 404 a through 404 d (only the four are shown in FIG.6) are formed in an array form on the upper surface of the firstdielectric layer 401, and a microstrip line 405 for antenna feeding isformed between the first dielectric layer 401 and the second dielectriclayer 402. Moreover, a ground layer 406 is formed between the seconddielectric layer 402 and the third dielectric layer 403, and a slot hole407 is formed in the ground layer 406. Moreover, microstrip lines 408 aand 408 b for a high-frequency circuit are formed on the surface of thethird dielectric layer 403, and MMIC's 409 a and 409 b, which aresemiconductor chips, are mounted on the microstrip lines 408 a and 408 bfor the high-frequency circuit. Then, the microstrip lines 408 a and 408b for the high-frequency circuit and the MMIC's 409 a and 409 b arecovered with a conductor lid 410.

[0068] Moreover, the ground layer 406 is connected to the conductor lid410 via through holes 411 c and 411 d and a connection portion 430. Oneend of a low-frequency signal line 413 is connected to the MMIC 409 b,and one end of a line 415 formed on the upper surface of the firstdielectric layer 401 is connected to the other end of the low-frequencysignal line 413 via the through hole 411 b. Then, a port 414 formed onthe surface of the third dielectric layer 403 is connected to the otherend of the line 415 via the through hole 411 a. A clearance hole 412through which the through hole 411 a penetrates is provided for theground layer 406.

[0069] The microstrip line 405 for antenna feeding iselectromagnetically coupled with the microstrip line 408 a for thehigh-frequency circuit via the slot hole 407 opened on the ground layer406. Moreover, the microstrip line 405 for antenna feeding iselectromagnetically coupled with the conductor patches 404 via the firstdielectric layer 401.

[0070] The antenna-integrated radio communication device of the thirdembodiment has the same effect as that of the first embodiment.

[0071] Moreover, this third embodiment differs from the first embodimentin that the port 414 of the low-frequency signal is provided on thelower surface of the dielectric multilayer substrate 420 and connectedto the low-frequency signal line 413 located inside the conductor lid410 via the through hole 411 a, the line 415 and the through hole 411 b.With this structure, an external device can be connected on the lowersurface side of the dielectric multilayer substrate 420, and therefore,the radiation pattern of the antenna is not disordered. In FIG. 6, theport 414 of the low-frequency signal is arranged on the lower surface ofthe dielectric multilayer substrate 420. However, in the case of a DCbias line of MMIC, it is also possible to arrange the port of the DCbias line on the lower surface of the dielectric multilayer substrateutterly in a similar manner.

Fourth Embodiment

[0072]FIG. 7 is a sectional view showing the structure of theantenna-integrated radio communication device of the fourth embodimentof this invention. As shown in FIG. 7, this antenna-integrated radiocommunication device includes a dielectric multilayer substrate 520 thathas a first dielectric layer 501, a second dielectric layer 502 and athird dielectric layer 503, which are laminated together. A plurality ofconductor patches 504 a through 504 d (only the four are shown in FIG.7) are formed in an array form on the upper surface of the firstdielectric layer 501. Moreover, a microstrip line 505 for antennafeeding is formed between the first dielectric layer 501 and the seconddielectric layer 502. Moreover, a ground layer 506 is formed between thesecond dielectric layer 502 and the third dielectric layer 503, and aslot hole 507 is formed in the ground layer 506. Moreover, microstriplines 508 a and 508 b for a high-frequency circuit are formed on thesurface of the third dielectric layer 503, and MMIC's 509 a and 509 b,which are semiconductor chips, are mounted on the microstrip lines 508 aand 508 b for the high-frequency circuit. Then, the microstrip lines 508a and 508 b for the high-frequency circuit and the MMIC's 509 a and 509b are covered with a conductor lid 510.

[0073] Moreover, the ground layer 506 is connected to the conductor lid510 via through holes 511 c and 511 d and a connection portion 530.Moreover, one end of a low-frequency signal line 513 is connected to theMMIC 509 b, and one end of a line 515 formed between the firstdielectric layer 401 and the second dielectric layer 402 is connected tothe other end of the low-frequency signal line 513 via the through hole511 b. Then, a port 514 formed on the surface of the third dielectriclayer 503 is connected to the other end of the line 515 via the throughhole 511 a. A clearance hole 512 through which the through hole 511 apenetrates is provided for the ground layer 506.

[0074] The microstrip line 505 for antenna feeding iselectromagnetically coupled with the microstrip line 405 a for thehigh-frequency circuit via the slot hole 507. Moreover, the microstripline 505 for antenna feeding is electromagnetically coupled with theconductor patches 504 via the first dielectric layer 501.

[0075] The antenna-integrated radio communication device of the fourthembodiment has the same effect as that of the third embodiment.

[0076] This fourth embodiment differs from the third embodiment in thatthe port 514 of the low-frequency signal is connected to thelow-frequency signal line 513 located inside the conductor lid 510 viathe line 515 of the internal layer (located between the first and seconddielectric layers 501 and 502) of the dielectric multilayer substrate520. With this structure, the line 515 for the low-frequency signal isarranged inside the dielectric multilayer substrate 520 with respect tothe conductor patches 504 a through 504 d, and therefore, the radiationpattern is not disordered by the signal line. In FIG. 7, the port of thelow-frequency signal is arranged on the lower surface side of thedielectric multilayer substrate 520. However, in the case of a DC biasline of MMIC, it is also possible to arrange the port of the DC biasline on the lower surface side of the dielectric multilayer substrateutterly in a similar manner.

[0077] In the first through fourth embodiments, by obtaining thedielectric layers of the dielectric multilayer substrates 220, 320, 420and 520 by integrally baking a ceramic material that has a relativedielectric constant of 4 to 10, the structure of the dielectricmultilayer substrate can be accurately obtained. Furthermore, by virtueof the use of the ceramic material, a strong substrate strength can beobtained, restraining the substrate warp and allowing the semiconductorchip mounting reliability to be improved.

Fifth Embodiment

[0078]FIG. 10 is a sectional view showing the structure of theantenna-integrated radio communication device of the fifth embodiment ofthis invention. The antenna-integrated radio communication device havingan antenna section that employs 64-element conductor patches will bedescribed below.

[0079] As shown in FIG. 10, the antenna-integrated radio communicationdevice includes a dielectric multilayer substrate 620 that has a firstdielectric layer 601, a second dielectric layer 602 and a thirddielectric layer 603, which are laminated together. In this case, glassceramic having a dielectric constant of 5.7, a dielectric loss tangentof 0.0019 and a layer thickness of 150 microns is used as a dielectricsubstance for the first through third dielectric layers 601, 602 and603. Conductor patches 604 and so on are formed in an array form on theupper surface of the first dielectric layer 601. One element of theconductor patches 604 has a dimension of 1.18 mm×0.84 mm. Moreover, amicrostrip line 605 for antenna feeding is formed between the firstdielectric layer 601 and the second dielectric layer 602. The conductorpatches 604 and the microstrip line 605 for antenna feeding constitutean antenna section. Moreover, a ground layer 606 is formed between thesecond dielectric layer 602 and the third dielectric layer 603, and aslot hole 607 is formed in the ground layer 606. Moreover, ahigh-frequency microstrip line 608 is formed on the surface of the thirddielectric layer 603, and surface mounting type components such as amillimeter wave package 609, package transistors 610 and 611 and a chipcapacitor 612 are mounted on the high-frequency microstrip line 608 bysoldering. Although not shown, a millimeter wave amplifier MMIC, amillimeter wave filter, a millimeter wave mixer MMIC and so on aremounted inside the millimeter wave package 609 by wire bonding orsimilar means.

[0080]FIG. 11 shows the positional relation of the conductor patches604, the microstrip line 605 for antenna feeding and the slot hole 607.An interval between the conductor patches 604 is 3.2 mm, whichcorresponds to 0.64λ0. In this case, λ0 has a free space wavelength ofabout 5 mm at 60 GHz.

[0081]FIG. 12 through FIG. 14 show the characteristics of the antennasection that employs the aforementioned 64-element conductor patches.That is, FIG. 12 shows the frequency characteristic of the antenna gainof the antenna section. The horizontal axis represents the frequency,and the vertical axis represents the antenna gain. FIG. 13 shows thefrequency characteristic of the input reflection loss S11 of the antennasection. The horizontal axis represents the frequency, and the verticalaxis represents the input reflection loss S11. FIG. 14 shows theradiation pattern of the above-mentioned antenna at 60 GHz. Thecharacteristics shown in FIG. 12 through FIG. 14 indicate that theantenna gain is about 20 dBi and the input reflection losscharacteristic is 10 dB or more over the wide band of about 59 GHz to 63GHz, meaning that the antenna section satisfactorily operates.

[0082] As described above, the circuit of a frequency of not higher than30 GHz is formed of inexpensive package transistors and so on, while thecircuit of the millimeter waves at 60 GHz or the like, at which the lossat the connection portion becomes a problem, is mounted inside themillimeter wave package with MMIC's and mounted on the surface of thedielectric multilayer substrate. With the above-mentioned structure, thecost of the antenna-integrated radio communication device can bereduced. Moreover, since the ceramic material such as glass ceramic isused for the dielectric multilayer substrate, there is a littledeformation due to heat, and the high mounting reliability of thesurface mounting components can be obtained.

[0083] Moreover, in the sixth embodiment, the first through thirddielectric layers 601, 602 and 603 have a thickness of 150 microns.However, by setting the thickness of each layer to 100 microns to 200microns, satisfactory transmission characteristics of the antennafeeding microstrip line can be obtained.

Sixth Embodiment

[0084]FIG. 15 is a block diagram showing the construction of atransmitter and a receiver, which employ the antenna-integrated radiocommunication device of the sixth embodiment of this invention. In FIG.15, the transmitter is constructed of a modulation signal source 701, aneven higher harmonic mixer 702, a bandpass filter 703, a power amplifier704, an antenna 705, a 16× multiplier 706 and a reference signal source707. In this case, the modulation signal source 701 is to output imagesand data and outputs, for example, an intermediate frequency signal of abroadcasting satellite and a communications satellite. On the otherhand, the receiver is constructed of a tuner 711, an even higherharmonic mixer 712, a bandpass filter 713, a low-noise amplifier 714, anantenna 715, a 16× multiplier 716 and a reference signal source 717.

[0085] The even higher harmonic mixer 702, the bandpass filter 703 andthe power amplifier 704 of the transmitter are housed in a millimeterwave package 708, while the even higher harmonic mixer 712, the bandpassfilter 713 and the low-noise amplifier 714 are housed in a millimeterwave package 718 of the receiver. The millimeter wave packages 708 and718 correspond to the millimeter wave package 609 shown in FIG. 10,while the antennas 705 and 715 correspond to the 64-element antennashown in FIG. 11. Moreover, the 16× multipliers 706 and 716 are formedof package transistors, chip capacitors, chip resistors, microstriplines and the like on the surface of the third dielectric layer as shownin FIG. 10.

[0086] In the transmitter of the above-mentioned construction, anintermediate-frequency signal generated by the modulation signal source701 occupies the frequencies of 1 GHz to 3 GHz and is inputted to theintermediate-frequency signal terminal of the even higher harmonic mixer702. Moreover, a sine-wave signal at a frequency of 1.84375 GHzgenerated by the reference signal source 707 becomes a local oscillationsignal of a 29.5-GHz sine wave obtained by multiplying the frequency bysixteen times by the 16× multiplier 706 and inputted to the localoscillation signal terminal of the even higher harmonic mixer 702. Then,the intermediate-frequency signal is mixed with the local oscillationsignal in the even higher harmonic mixer 702. Among the signalsgenerated from the even higher harmonic mixer 702, only thehigh-frequency signals within the frequency range of 60 GHz to 62 GHzpass through the bandpass filter 703 and is inputted to and amplified bythe power amplifier 704 and radiated as high-frequency radio waves 720from the antenna 705.

[0087] Then, the high-frequency radio waves 720 radiated from theantenna 705 of the transmitter are received by the antenna 715 of thereceiver so as to become a high-frequency signal and amplified by thelow-noise amplifier 714. Further, the high-frequency signal amplified bythe low-noise amplifier 714 passes through the bandpass filter 713 andis inputted to the high-frequency signal terminal of the even higherharmonic mixer 712. The sine-wave signal, which is generated by thereference signal source 717 and the 16× multiplier 716 and has afrequency of 29.5 GHz, is inputted to the local oscillation signalterminal of the even higher harmonic mixer 712 similarly to theaforementioned transmitter. Then, the inputted high-frequency signal ismixed with a local oscillation signal inside the even higher harmonicmixer 712 and reconverted into an intermediate-frequency signal withinthe frequency range of 1 GHz to 3 GHz. The intermediate-frequency signalconverted by the even higher harmonic mixer 712 is inputted to the tuner711 and converted into the desired information by the tuner 711.

[0088] The antenna 705 and the antenna 715 may have same construction,while the 16× multiplier 706 and the 16× multiplier 716 may have sameconstruction. That is, portions other than the millimeter wave packageof the antenna-integrated radio communication device may be shared bythe transmitter and the receiver.

[0089] As described above, by constructing a transmitter and a receiverwith the antenna-integrated radio communication device of thisinvention, the transmitter and the receiver can be downsized. Moreover,by virtue of the formation of the antenna section and the high-frequencycircuit on the upper and lower surfaces, respectively, of the dielectricsubstrate, it is allowed to reduce the transmission loss of the signalbetween the antenna section and the high-frequency circuit and increasethe communication distance without increasing consumption power.

1. An antenna-integrated radio communication device having a dielectricmultilayer substrate (220) in which a plurality of dielectric layers arelaminated and a high-frequency circuit on which semiconductor chips (209a, 209 b) are mounted, wherein a plurality of conductor patches (204a-204 d), an antenna feeder line (205) for feeding the plurality ofconductor patches (204 a-204 d), one ground layer (206) and thehigh-frequency circuit connected to the antenna feeder line (205) areseparately arranged on an upper surface, between layers and on a lowersurface, respectively, of the dielectric multilayer substrate (220), andthe one ground layer (206) is arranged between an antenna sectioncomprised of the plurality of conductor patches (204 a-204 d) and theantenna feeder line (205) and the high-frequency circuit.
 2. Theantenna-integrated radio communication device as claimed in claim 1,wherein the dielectric multilayer substrate (220) is a dielectricmultilayer substrate comprised of a first dielectric layer (201), asecond dielectric layer (202) and a third dielectric layer (203), theplurality of conductor patches (204 a-204 d) are arranged on an uppersurface of the first dielectric layer (201) of the dielectric multilayersubstrate (220), the antenna feeder line (205) is arranged between thefirst dielectric layer (201) and the second dielectric layer (202), theground layer (206) is arranged between the second dielectric layer (202)and the third dielectric layer (203), the high-frequency circuit isarranged on a lower surface of the third dielectric layer (203) of thedielectric multilayer substrate (220), and the antenna feeder line (205)is electromagnetically coupled with the high-frequency circuit via aslot hole (207) provided for the ground layer (206).
 3. Theantenna-integrated radio communication device as claimed in claim 1,wherein the plurality of conductor patches (304) are arranged in anarray form, the antenna feeder line (305) is branched into a pluralityof lines, and the plurality of conductor patches (304) and end portionsof the branches of the antenna feeder line (305) overlap each other. 4.The antenna-integrated radio communication device as claimed in claim 3,wherein a distance in a lengthwise direction of the antenna feeder line(305) in a region where the plurality of conductor patches (304) and theend portions of the branches of the antenna feeder line (305) overlapeach other is approximately a quarter of an effective wavelength of aprescribed electromagnetic wave.
 5. The antenna-integrated radiocommunication device as claimed in claim 1, wherein the dielectriclayers of the dielectric multilayer substrate (220) are formed byintegrally baking a ceramic material that has a relative dielectricconstant of 4 to
 10. 6. An antenna-integrated radio communicationdevice, wherein a plurality of conductor patches (604), an antennafeeder line (605), a ground layer (606) and a high-frequency circuit areprovided in order from an upper surface to a lower surface of thedielectric multilayer substrate (620) on the upper surface, betweenlayers and on the lower surface, respectively, of the dielectricmultilayer substrate (620) in which three dielectric layers arelaminated.
 7. The antenna-integrated radio communication device asclaimed in claim 6, wherein each dielectric layer of the dielectricmultilayer substrate (620) has a thickness of 100 microns to 200microns.
 8. A transmitter employing the antenna-integrated radiocommunication device claimed in claim
 6. 9. A receiver employing theantenna-integrated radio communication device claimed in claim 6.